Electric motor powered appliances such as blow dryers and other heated-air dryers typically have a much shorter service life than one might expect. This is attributable to the ingestion of foreign particulate material through the blower intake and the consequent abrasion and corrosion of the blower's operating components by the foreign particles. This problem is as old as blow dryers themselves and is present because available blow dryers either have no mechanism at all for filtering particles from the incoming air or, at best, a rudimentary and ineffective, particle-trapping screen or an equally ineffective filter woven or otherwise fabricated from elongated filaments. Of this character are the screens and filters disclosed in U.S. Pat. Nos.: 3,418,452 issued 24 Dec. 1968 to Grabner; 4,634,839 issued 6 Jan. 1987 to Gilbertson; 3,857,016 issued 24 Dec. 1974 to Meyer et al.; and 5,216,822 issued 8 Jun. 1993 to Madiedo.
The screens and filters disclosed in this just-cited patents and others of the same, currently available character are at best capable of trapping gross particles such as large pieces of hair and lint. Dust particles, small fragments of hair, hair spray droplets, and other minute particles readily pass through these prior art screens and filters; and it is the smaller particles which are most apt to penetrate into the working components of the appliance and cause the damage leading to shortened service life.
One might expect that aftermarket or replacement filters capable of trapping those small particles most apt to damage the working components of a heated-air blower would be available. That they are not is believed to be attributable to the cost of manufacturing and stocking the large number of different filters that would be required to outfit the variety of hand held blowers currently available in the marketplace and to the lack of a filtration device having a universal character making it compatible with the different hair dryers that are currently in use and available for purchase.
Consequently, there has been a continuing need which currently persists for a filter which is: (a) effective to trap minute as well as gross particles without unexceptably impeding the flow of air through a heated-air blower or other appliance; and (b) a filtration device of that character which is universally adaptable to currently used and marketed blowers as well as those which may become available in the future.